KR20220117281A - Thermoplastic molding composition comprising polyalkylene terephthalate - Google Patents

Abstract

The present invention relates to a thermoplastic molding compound comprising a polyalkylene terephthalate and a polyimide, wherein the molding compound has a single glass transition temperature as measured by DSC. The present invention further relates to their use and to fibers, films and molded articles produced from the molding compositions.

Description

Thermoplastic molding composition comprising polyalkylene terephthalate

The present invention relates to a thermoplastic molding compound comprising a polyalkylene terephthalate and a polyimide, wherein the molding compound has a single glass transition temperature. The present invention further relates to their use and to fibers, films and shaped bodies prepared from the molding compounds.

Polyalkylene terephthalate is a polyester and has thermoplastic properties. It has a wide variety of possible applications. Polyethylene terephthalate (PET) plays a particularly important role. PET is used inter alia to make plastic bottles (PET bottles), films and textile fibers. Polybutylene terephthalate (PBT) has good properties. PBT is preferred over PET because of its better processing properties, which is particularly important in the injection molding process. However, the starting material of PBT is more expensive.

A disadvantage of polyalkylene terephthalate is its relatively low glass transition temperature (T _g ). This limits the temperature range for the rigid elastic state in which polyalkylene terephthalates are often used, and it is desirable to extend this temperature range and increase the glass transition temperature. It is likewise desirable to maintain the properties of polyalkylene terephthalates, such as their crystallinity, to the maximum possible extent, and to allow them to be increased via additives in the molding compound.

Accordingly, it is an object of the present invention to provide such molding compounds.

This object has been achieved by a thermoplastic molding compound comprising polyalkylene terephthalate and a polyimide, wherein the molding compound has a single glass transition temperature in DSC measurement.

Surprisingly, the mixture of polyalkylene terephthalate and polyimide uniquely forms one amorphous phase, whereby heating of the mixture exhibits only a single glass transition temperature, and the glass transition of the components polyalkylene terephthalate and polyimide found that no longer occurs.

In the context of the present invention, the term "molding compound" is used according to its generally understood definition. The molding compound is thus an unshaped product, which can be molded by mechanical force in a certain temperature range. Suitable processes are, for example, extrusion, injection molding and pressing.

The glass transition temperature (T _g ) is known to the person skilled in the art and represents a characteristic physical parameter of a polymer or mixture of two or more polymers. At this temperature, the solid polymer or glass transforms into a rubber-like to viscous state. This can be measured, for example, by dynamic scanning calorimetry (DSC).

The thermoplastic molding compounds according to the invention have a single glass transition temperature. The expression "single glass transition temperature" is to be understood in the context of the present invention in a simplified form, meaning that the polymeric polyimide and polyalkylene terephthalate form a mixed phase with a T _g value between the T _g values of the components. do. Further auxiliaries which may be present in the thermoplastic molding material according to the invention may themselves have polymeric, amorphous properties and may have a glass transition temperature, but should not be considered in the context of having a “single glass transition temperature”. Can not be done.

This single glass transition temperature T _g preferably has a value of at least 45 °C. A T _g of at least 50° C. is more preferable. A T _g of at least 60° C. is even more preferred. A T _g of at least 70° C. is even more preferred. A T _g of at least 80° C. is even more preferred.

According to the invention, polyimides characterized by high T _g values are typically used to increase the T _g values of low polyalkylene terephthalates. Accordingly, the T _{g value of the thermoplastic molding compound is within a range starting from the T g value of the polyalkylene terephthalate and ending with the T g value of} the polyimide.

The difference between the T _g value of the polyimide and the T _g value of the polyalkylene terephthalate before introduction into the molding compound according to the invention is at least 25° C., more preferably at least 50° C., more preferably at least 75° C., More preferably, it is at least 100°C, more preferably at least 125°C, more preferably at least 130°C, even more preferably at least 140°C.

The difference (increase) between the T _g value of the polyalkylene terephthalate before introduction into the molding compound according to the invention and the T _g value of the polyalkylene terephthalate in the molding compound according to the invention (mixed phase) is at least 5°C, more preferably at least 10°C, more preferably at least 15°C, more preferably at least 20°C, more preferably at least 25°C, more preferably at least 30°C, more preferably at least 40°C It is preferable if

The thermoplastic molding compound according to the invention comprises polyalkylene terephthalate. It is preferably polyethylene, polytrimethylene or polybutylene terephthalate or mixtures thereof. It is more preferably polybutylene terephthalate.

Polyalkylene terephthalate (A) is commercially available and may comprise at least partially amorphous form. In the context of the present invention, a polyalkylene terephthalate may have a glass transition temperature assigned to it.

The commercially available polybutylene terephthalate (A) is for example sold by BASF as the Ultradur® series. An example is Ultradur® B4500.

Commercially available polyethylene terephthalate (A) is for example sold by BASF as the Petra® series.

The thermoplastic molding compound according to the invention further comprises polyimide (B).

Polyimide (B) is a very stable polymer both thermally and mechanically. To make these polymers available as thermoplastics, irregularities are introduced into the polymer chains. For example, branching in a polymer scaffold may be provided. This branching avoids crystallinity and makes it possible to adjust the T _g values.

An exemplary synthesis of polyimide is shown below, where only one polymer unit is shown as an excerpt for simplicity.

The presence of small amounts of water can have a catalytic effect on the reaction, wherein the removal of carbon dioxide makes the polyimide soluble in NMP, for example.

The catalytic effect of water is shown in the following reaction sequence:

The preparation of polyimides is known, for example, from WO 2012/163680 A1 and is described more specifically below. Polyimides can be formed, for example, from:

b1) at least one isocyanate, preferably at least having an average of more than two isocyanate groups per molecule, wherein the isocyanate comprises at least two isocyanate groups (“polyisocyanates”),

b2) at least one amine (“polyamine”), preferably at least one amine having an average of more than two amino groups per molecule, wherein the amine comprises at least two amino groups, and

b3) at least one polycarboxylic acid having at least 3, preferably at least 4 and particularly precisely 4 COOH groups per molecule, or an anhydride thereof, in particular a dianhydride.

Combinations b1) and b3) are preferred.

The polyimides (B) are particularly preferably obtained by reaction of at least one carboxylic dianhydride with at least one isocyanate, wherein the isocyanate comprises at least two, preferably more than two isocyanate groups.

The polyimide (B) may have a molecular weight Mw in the range from 1000 to 200 000 g/mol, preferably at least 2000 g/mol.

The polyimide (B) may have at least 2 imide groups per monomer unit, preferably at least 3 imide groups per monomer unit.

In one embodiment of the present invention, the polyimide (B) may comprise at most 1000 imide groups per molecule, preferably at most 660 imide groups per molecule. In one embodiment of the invention, the reported number of isocyanate groups/COOH groups in each case refers to the average (number average).

The polyimide (B) may be composed of structurally and molecularly homogeneous molecules. However, the polyimide (B) is a mixture of molecularly and structurally distinct molecules visible, for example, at a polydispersity Mw/Mn of at least 1.4; Mw/Mn may be preferably 1.4 to 50, more preferably 1.5 to 10. The polydispersity can be determined by known methods, in particular by gel permeation chromatography (GPC). A suitable standard is, for example, polymethyl methacrylate (PMMA). In addition to the imide groups forming the polymer scaffold, the polyimide (B) may further comprise at least 3, preferably at least 6, particularly preferably at least 10 terminal or pendant functional groups in terminal or pendant positions. . The functional groups in the polyimide (B) can be, for example, anhydride or acid groups and/or free or capped NCO groups. The polyimide (B) preferably contains up to 500, preferably up to 100 terminal or pendant functional groups.

The polyisocyanate (b1) may be selected from any desired polyisocyanate comprising an average of at least two or preferably more than two isocyanate groups per molecule, which may be capped or preferably free. of trimeric or oligomeric diisocyanates, for example oligomeric hexamethylene diisocyanate, oligomeric isophorone diisocyanate, oligomeric tolylene diisocyanate, oligomeric diphenylmethane diisocyanate - so-called polymeric MDI - and of the polyisocyanates described above. Mixtures are preferred. The so-called trimeric hexamethylene diisocyanate is in many cases not in the form of a pure trimeric diisocyanate, but rather in the form of a polyisocyanate having an average functionality of 3.6 to 4 NCO groups per molecule. Similar applies for oligomeric tetramethylene diisocyanate and oligomeric isophorone diisocyanate.

The polyisocyanates described above are commercially available or can be prepared by known methods. For example, polymeric MDI is available as Lupramat®. For example, Lupramat M20 has an average isocyanate functionality of 2.7.

In one embodiment of the invention, the polyisocyanate is a polyisocyanate having more than two isocyanate groups per molecule, a mixture of at least one diisocyanate and at least one triisocyanate and a polyisocyanate having at least 4 isocyanate groups per molecule.

In one embodiment of the invention the polyisocyanate (b1) has an average of at least 2.2, preferably at least 2.5 and particularly preferably at least 3.0 isocyanate groups per molecule.

In one embodiment of the invention the polyisocyanate (b1) is selected from oligomeric hexamethylene diisocyanate, oligomeric isophorone diisocyanate, oligomeric diphenylmethane diisocyanate and mixtures of the aforementioned polyisocyanates.

Polyisocyanates (b1) contain not only isocyanate groups but also one or more other functional groups, for example urethanes, ureas, allophanates, biurets, carbodiimides, amides, esters, ethers, uretonimines, uretdiones, isocyanus. rate or oxazolidine groups. In a second variant, the polyamine (b2) and the polycarboxylic acid b3) and/or the polycarboxylic acid ester (b3) can be reacted with each other analogously to the process described in US 2010/009206 A1. The polyamine (b2) may be selected from any desired polyamine comprising an average of more than two isocyanate groups per molecule, which may be capped or preferably free.

Suitable polyamines (b2) are also for example 3,5-di(4-aminophenoxy)aniline, 3,5-di(3-methyl-1,4-aminophenoxy)aniline, 3,5-di( 3-methoxy-4-aminophenoxy)aniline, 3,5-di(2-methyl-4-aminophenoxy)aniline, 3,5-di(2-methoxy-4-aminophenoxy)aniline, compounds recited in US 2010/009206 A1 such as 3,5-di(3-ethyl-4-aminophenoxy)aniline and the like. Also, amines such as 1,3,5-tri(4-aminophenoxy)benzene, 1,3,5-tri(3-methyl-1,4-aminophenoxy)benzene, 1,3,5-tri( 3-methoxy-4-aminophenoxy)benzene, 1,3,5-tri(2-methyl-4-aminophenoxy)benzene, 1,3,5-tri(2-methoxy-4-aminophenoxy) C)benzene and 1,3,5-tri(3-ethyl-4-aminophenoxy)benzene are suitable. In addition, as aromatic triamines, 1,3,5-tri(4-aminophenylamino)benzene, 1,3,5-tri(3-methyl-4-aminophenylamino)benzene, 1,3,5-tri( 3-Methoxy-4-aminophenylamino)benzene, 1,3,5-tri(2-methyl-4-aminophenylamino)benzene, 1,3,5-tri(2-methoxy-4-aminophenyl It is possible to use amino)benzene, 1,3,5-tri(3-ethyl-4-aminophenylamino)benzene and the like.

Additional aromatic triamines include 1,3,5-tri(4-aminophenyl)benzene, 1,3,5-tri(3-methyl-4-aminophenyl)benzene, 1,3,5-tri(3- Methoxy-4-aminophenyl)benzene, 1,3,5-tri(2-methyl-4-aminophenyl)benzene, 1,3,5-tri(2-methoxy-4-aminophenyl)benzene, 1 ,3,5-tri(3-ethyl-4-aminophenyl)benzene and similar compounds.

Also, 1,3,5-tri(4-aminophenyl)amine, 1,3,5-tri(3-methyl-4-aminophenyl)amine, 1,3,5-tri(3-methoxy-4 -Aminophenyl)amine, 1,3,5-tri(2-methyl-4-aminophenyl)amine, 1,3,5-tri(2-methoxy-4-aminophenyl)amine, 1,3,5 -tri(3-ethyl-4-aminophenyl)amine and similar compounds are suitable.

Further examples are tris(4-(4-aminophenoxy)phenyl)methane, tris(4-(3-methyl-4-aminophenoxy)phenyl)methane, tris(4-(3-methoxy-4- Aminophenoxy)phenyl)methane, tris(4-(2-methyl-4-aminophenoxy)phenyl)methane, tris(4-(2-methoxy-4-aminophenoxy)phenyl)methane, tris(4 -(3-ethyl,4-aminophenoxy)phenyl)methane and similar compounds.

Suitable amines are further tris(4-(4-aminophenoxy)phenyl)ethane, tris(4-(3-methyl-4′-aminophenoxy)phenyl)ethane, tris(4-(3-methoxy- 4-aminophenoxy)phenyl)ethane, tris(4-(2-methyl-4-aminophenoxy)phenyl)ethane, tris(4-(2-methoxy-4-aminophenoxy)phenyl)ethane, tris (4-(3-ethyl-4-aminophenoxy)phenyl)ethane and the like.

It is also possible to use the polyamines cited in US 2006/033225 A1. Also for example 3,3',4,4'-biphenyltetraamine (TAB), 1,2,4,5-benzenetetraamine, 3,3',4,4'-tetraaminodiphenyl ether, 3,3',4,4'-tetraaminodiphenylmethane, 3,3',4,4'-tetraaminobenzophenone, 3,3',4-triaminobiphenyl, 3,3',4- triaminodiphenylmethane, 3,3′,4-triaminobenzophenone, 1,2,4-triaminobenzene and mono-, di-, tri- or tetra-acid salts thereof such as 2,4,6-tri It is possible to use aminopyrimidines (TAPs).

The polycarboxylic acids (b3) used are preferably aliphatic or preferably aromatic polycarboxylic acids comprising at least 3 COOH groups per molecule or, respectively, when they are of low molecular weight, ie in their non-polymeric form. anhydrides. Also contemplated are polycarboxylic acids having three COOH groups in which two carboxylic acid groups are in the form of the anhydride and the third is in the form of the free carboxylic acid. In a preferred embodiment of the invention, the polycarboxylic acid (b3) is selected from polycarboxylic acids having at least 4 COOH groups per molecule or from respective anhydrides, in particular dianhydrides.

Examples of polycarboxylic acids (b3) and their anhydrides are 1,2,3-benzenetricarboxylic acid and 1,2,3-benzenetricarboxylic dianhydride, 1,3,5-benzenetricarboxylic acid (trimesic acid), preferably 1,2,4-benzenetricarboxylic acid (trimellitic acid), trimellitic anhydride and especially 1,2,4,5-benzenetracarboxylic acid (pyromellitic acid) and 1,2,4,5-benzenetracarboxylic dianhydride (pyromellitic dianhydride), 3,3',4,4"-benzophenonetetracarboxylic acid, 3,3',4,4" -benzophenonetetracarboxylic dianhydride, also anhydride of benzenehexacarboxylic acid (mellitic acid) and mellitic acid.

Also, mellophanic acid and mellophanic anhydride, 1,2,3,4-benzenetetracarboxylic acid and 1,2,3,4-benzenetetracarboxylic dianhydride, 3,3,4,4-biphenyltetra Carboxylic acid and 3,3,4,4-biphenyltetracarboxylic dianhydride, 2,2,3,3-biphenyltetracarboxylic acid and 2,2,3,3-biphenyltetracarboxylic acid dianhydride, 1,4,5,8-naphthalenetetracarboxylic acid and 1,4,5,8-naphthalenetetracarboxylic acid dianhydride, 1,2,4,5-naphthalenetetracarboxylic acid and 1,2 ,4,5-naphthalenetetracarboxylic dianhydride, 2,3,6,7-naphthalenetetracarboxylic acid and 2,3,6,7-naphthalenetetracarboxylic dianhydride, 1,4,5,8 -decahydronaphthalenetetracarboxylic acid and 1,4,5,8-decahydronaphthalenetetracarboxylic dianhydride, 4,8-dimethyl-1,2,3,5,6,7-hexahydronaphthalene-1 ,2,5,6-tetracarboxylic acid and 4,8-dimethyl-1,2,3,5,6,7-hexahydronaphthalene-1,2,5,6-tetracarboxylic dianhydride, 2 ,6-dichloronaphthalene-1,4,5,8-tetracarboxylic acid and 2,6-dichloronaphthalene-1,4,5,8-tetracarboxylic dianhydride, 2,7-dichloronaphthalene-1, 4,5,8-tetracarboxylic acid and 2,7-dichloronaphthalene-1,4,5,8-tetracarboxylic dianhydride, 2,3,6,7-tetrachloronaphthalene-1,4,5 ,8-tetracarboxylic acid and 2,3,6,7-tetrachloronaphthalene-1,4,5,8-tetracarboxylic dianhydride, 1,3,9,10-phenanthrenetetracarboxylic acid and 1,3,9,10-phenanthrenetetracarboxylic dianhydride, 3,4,9,10-perylenetetracarboxylic acid and 3,4,9,10-perylenetetracarboxylic dianhydride, bis (2,3-dicarboxyphenyl)methane and bis(2,3-dicarboxyphenyl)methane dianhydride, bis(3,4-dicarboxyphenyl)methane and bis(3,4-dicarboxyphenyl)methane dianhydride , 1,1-bis(2,3-dicarboxyphenyl)ethane and 1,1-bis(2,3-dicarboxyphenyl)ethane dianhydride, 1,1-bis(3,4-dicarboxyphenyl)ethane and 1,1-bis(3,4-dicarboxyphenyl)ethane dianhydride, 2,2-bis(2,3-dicar carboxyphenyl)propane and 2,2-bis(2,3-dicarboxyphenyl)propane dianhydride, 2,3-bis(3,4-dicarboxyphenyl)propane and 2,3-bis(3,4-di Carboxyphenyl)propane dianhydride, bis(3,4-carboxyphenyl)sulfone and bis(3,4-carboxyphenyl)sulfone dianhydride, bis(3,4-carboxyphenyl)ether and bis(3,4-carboxyphenyl) ) ether dianhydride, ethylenetetracarboxylic acid and ethylenetetracarboxylic dianhydride, 1,2,3,4-butanetetracarboxylic acid and 1,2,3,4-butanetetracarboxylic dianhydride, 1 ,2,3,4-cyclopentanetetracarboxylic acid and 1,2,3,4-cyclopentanetetracarboxylic dianhydride, 2,3,4,5-pyrrolidinetetracarboxylic acid and 2,3 ,4,5-pyrrolidinetetracarboxylic dianhydride, 2,3,5,6-pyrazinetetracarboxylic acid and 2,3,5,6-pyrazinetetracarboxylic dianhydride, 2,3,4 ,5-thiophenetetracarboxylic acid and 2,3,4,5-thiophenetetracarboxylic dianhydride are suitable.

It is preferred if the at least one carboxylic dianhydride is 1,2,4,5-benzenetetracarboxylic anhydride.

In one embodiment of the invention the anhydride from US 2,155,687 A or US 3,277,117 A is used to synthesize the polyimide (B).

The production of polyimide (B) may follow the mechanism shown in the following formula. The polyisocyanate (b1) and the polycarboxylic acid (b3) are reacted with each other, preferably in the presence of a catalyst, to remove CO ₂ and H ₂ O to form imide groups. The polyisocyanate (b1) and the corresponding anhydride (b3) are reacted with each other to remove CO ₂ , thereby forming an imide group.

wherein R** is a polyisocyanate (b2) radical not further specified in the formula, and n is a number equal to or greater than one. When n is 1, for example, it is a tricarboxylic acid. When n = 2, for example, it is a tetracarboxylic acid. (HOOC)n may be replaced by a C(=O)-O-C(=O) or ester radical.

The polyamine (b2) and the polycarboxylic acid (b3)/corresponding anhydride (b3) are reacted, preferably in the presence of a catalyst, to form the imide moiety by removal of water.

wherein R* is a polyamine (b2) radical not further specified in the formula. n is a number greater than or equal to 1. In the case of tricarboxylic acids, n=1. In the case of tetracarboxylic acids, n=2. (HOOC)n may be replaced by a C(=O)-O-C(=O) radical or an ester.

Polyimide B) can be produced, for example, by the process described below.

The polyisocyanate (b1) and the polycarboxylic acid (b3) are condensed with each other, preferably in the presence of a catalyst - CO ₂ and The imide group is formed by removing H ₂ O. If the corresponding anhydride is used instead of the polycarboxylic acid (b3), the imide group is formed by removal of CO ₂ .

Suitable catalysts are in particular water and Bronsted bases, for example alkali metal alkoxides, in particular alkoxides of sodium or potassium, for example sodium methoxide, sodium ethoxide, sodium phenoxide, potassium methoxide, potassium ethoxide, potassium phenoxide side, lithium methoxide, lithium oxide and lithium phenoxide. The catalyst may be employed in a range from 0.005% to 0.1% by weight, based on the sum of polyisocyanate (b1) and polycarboxylic acid (b3)/polyisocyanate (b1) and anhydride (b3). 0.01% to 0.05% by weight of catalyst is preferred.

If the polyisocyanate (b1) comprises >2 isocyanate groups, it can be used in admixture with at least one diisocyanate, for example with tolylene diisocyanate, hexamethylene diisocyanate or with isophorone diisocyanate. In certain variants, the polyisocyanates (b1) are the corresponding diisocyanates, for example trimeric HDI and hexamethylene diisocyanate or trimeric isophorone diisocyanate and isophorone diisocyanate or oligomeric diphenylmethane diisocyanate (polymeric MDI) and diphenylmethane diisocyanate are mixed and used.

In a particularly preferred embodiment, the at least one isocyanate is 4,4'-diphenylmethane diisocyanate, oligomeric 4,4'-diphenylmethane diisocyanate, 2,4-toluene diisocyanate or 2,6-toluene diisocyanate or a mixture thereof. Particular preference is given to using mixtures of at least three isocyanates, in particular oligomeric 4,4'-diphenylmethane diisocyanate, 2,4-toluene diisocyanate and 2,6-toluene diisocyanate. The molar ratio of 2,4-toluene diisocyanate to 2,6-toluene diisocyanate is from 1:1 to 10:1, more preferably from 1.5:1 to 8:1, more preferably from 2:1 to 6:1; More preferably, it is in the range of 3:1 to 5:1, particularly preferably in the case of 4:1.

The molar ratio of oligomeric 4,4-diphenylmethane diisocyanate to the sum of 2,4-toluene diisocyanate and 2,6-toluene diisocyanate is preferably 1:1 to 0.1:1, more preferably 0.8:1 to 0.2:1, more preferably 0.7:1 to 0.3, more preferably 0.5:1 to 0.4:1.

The polycarboxylic acid (b3) can be used in admixture with at least one dicarboxylic acid or with at least one dicarboxylic anhydride, for example with phthalic acid or phthalic anhydride.

In one embodiment of the present invention, the polyimide (B) used is a hyperbranched polyimide. In the context of the present invention, the term "hyperbranched" refers to the degree of branching (DB), ie the average number of dendritic bonds per molecule plus the average number of end groups of the average number of branched, linear and terminal bonds. Divided by the sum and multiplied by 100 should be understood to mean between 10% and 99.9%, preferably between 20% and 99%, particularly preferably between 20% and 95%. In the context of the present invention, "dendrimers" should be understood to mean a degree of branching of 99.9-100%. For the definition of "degree of branching" see H. Frey et al., Acta Polym. 1997, 48, 30, and Sunder et al., Chem. Eur. J. 2000, 6 (14), 2499-2506. The degree of branching can be calculated using “reverse-gated” 13NMR spectra.

Polyimide B) comprises polyisocyanate (b1) and polycarboxylic acid (b3) in a molar ratio in which the mole fraction of NCO groups to COOH groups ranges from 1: 3 to 3: 1, preferably from 1: 2 to 2: 1. /anhydride (b3). Anhydride groups of the formula CO—O—CO count as two COOH groups.

Polyimide B) is preferably produced at a temperature in the range from 50°C to 200°C, preferably from 50°C to 140°C, particularly preferably from 50°C to 100°C.

Compound B) can be prepared in the presence of a solvent or solvent mixture. Examples of suitable solvents include N-methylpyrrolidone (NMP), N-ethylpyrrolidone, dimethylformamide (DMF), dimethylacetamide, dimethylsulfoxide, dimethylsulfone, xylene, phenol, cresol, ketones such as acetone, methyl ethyl ketone (MEK), methyl isobutyl ketone (MIBK), acetophenone, also monochlorobenzene and dichlorobenzene, ethylene glycol monoethyl ether acetate and mixtures of two or more of the aforementioned solvents. The solvent(s) may be present during the entire course of the synthesis or only during a portion of the synthesis.

Polyimide B) can further be prepared under an inert gas, for example under argon or under nitrogen. In particular, when a moisture-sensitive Bronsted base is used as the catalyst, drying of the inert gas and solvent is preferred. Drying of the solvent and inert gas can be avoided when water is used as the catalyst.

Similar to the reactions of b1) and b3), polyimide B) can be prepared by reacting b2) and b3) under the same conditions.

Polyimide B) can also be prepared by reacting b2) with b3) as described in US 2006/033225 A1.

In one variant of the polyimide (B), the NCO end groups of the polyimide (B) are blocked with an NCO-reactive compound. It can be, for example, a secondary amine (b4).

Suitable secondary amines (b4) are, for example, compounds of the form NHR'R", wherein R' and R" may be aliphatic and/or aromatic radicals. Aliphatic radicals may be linear, cyclic and/or branched. R′ and R″ may be the same. However, R′ and R″ are not hydrogen atoms.

Suitable amines (b4) are, for example, dimethyl amine, di-n-butylamine or diethylamine or mixtures thereof. Also suitable are dihexylamine, di-(2-ethylhexyl)amine and dicyclohexylamine. Diethylamine and dibutylamine are preferred.

Polyimide (B) can also be blocked with alcohol (b5). Primary alcohols or mixtures thereof are suitable. Suitable candidates from the group of primary alcohols include, inter alia, methanol, ethanol, isopropanol, n-propanol, n-butanol, isobutanol. Methanol, isobutanol and tert-butanol are preferred. tert-butanol is particularly preferred.

Of the alternatives (b4) and (b5), (b5) is preferred.

It is therefore more preferred if the reaction of the at least one carboxylic acid dianhydride with the at least one isocyanate is followed by a reaction with an alcohol or an amine, preferably an alcohol, in particular tert-butanol to react the unconverted isocyanate.

The polyimide (B) preferably has an isocyanate content of less than 1% by weight, based on the total weight of the polyimide. It is particularly preferred if the polyimide does not contain isocyanates.

It is preferred if the ratio of the weight fraction of polyalkylene terephthalate to polyimide ranges from 1:1 to 9.9:1, preferably from 2:1 to 9:1, more preferably from 3:1 to 4:1. do.

The proportion of polyalkylene terephthalate based on the total weight of the molding compound is at least 50% by weight, more preferably more than 50% by weight. However, the proportion may also range, for example, from 25% to 70% by weight, based on the total weight of the molding compound.

The proportion of polyimide, based on the total weight of the molding compound, is preferably 50% by weight or less, more preferably less than 50% by weight. However, the proportion may also range, for example, from 5% to 30% by weight, based on the total weight of the molding compound.

The thermoplastic molding compound according to the present invention may contain additional components other than polyalkylene terephthalate and polyimide.

The thermoplastic molding compounds according to the invention as component C) contain conventional processing aids such as stabilizers, oxidation retardants, agents against thermal decomposition and ultraviolet decomposition, lubricants and mold release agents, colorants such as dyes and pigments, nucleating agents, plasticizers, etc. can do. In particular flame retardants may be present.

Examples of oxidation retardants and heat stabilizers are sterically hindered phenols and/or phosphites and amines (eg TAD), hydroquinones, aromatic secondary amines such as diphenyl in concentrations of up to 1% by weight, based on the weight of the thermoplastic molding compound. amines, various substituted representatives of these groups, and mixtures thereof.

Examples of UV stabilizers commonly employed in amounts of up to 2% by weight based on the thermoplastic molding compound include various substituted resorcinols, salicylates, benzotriazoles and benzophenones.

Colorants that may be added include inorganic pigments such as carbon black and organic pigments such as phthalocyanines, quinacridones, perylenes and also pigments such as anthraquinones.

Nucleating agents that can be used include sodium phenylphosphinate, alumina, silica.

It is further possible to use glass particles comprising glass fibers of various dimensions.

Glass fibers are for reinforcing, therefore it is preferred if reinforcing fibers, in particular glass fibers, are present in the thermoplastic molding compound according to the invention. The proportion is preferably from 5% to 70% by weight, more preferably from 10% to 60% by weight, even more preferably from 15% to 50% by weight, based on the total weight of the thermoplastic molding compound according to the invention, Even more preferably 20% to 40% by weight, in particular 30% by weight.

If component C is present, preference is given to the following proportions, based on the total weight of the thermoplastic molding compound according to the invention.

25% to 65% by weight of polyalkylene terephthalate,

5% to 30% by weight of polyimide,

5% to 70% by weight of component C, preferably in the form of reinforcing fibers, in particular glass fibers.

Thermoplastic molding compounds can be prepared, for example, by simple mixing in an extruder. After the molding process, it is possible from the molding compound to obtain a molded article extending substantially in one dimension (thread), a molded article extending substantially in two dimensions (film) or a molded article extending substantially in three dimensions (molding body) do.

The mechanical properties of the thermoplastic molding compounds according to the invention favor the use of thermoplastic molding compounds for producing fibers, films and/or moldings. The thermoplastic compositions are particularly suitable for producing special shaped bodies in vehicle and machine construction, for example for industrial or consumer-oriented applications. Thermoplastic molding compounds can therefore be used in electronic components, housings, housing components, cover flaps, bumpers, spoilers, autobody components, springs, handles, charge air pipes, automotive interior applications such as Instrument panels, parts of instrument panels, instrument panel carriers, covers, air ducts, air inlet meshes, sunroof cassettes, roof frames, add-on parts, especially parts of gloveboxes It can be used to manufacture center consoles or other instrument binnacles such as

The thermoplastic molding compounds according to the invention can also be used as coating compositions for fibers, films and/or moldings. The term shaped body should be understood to refer to a three-dimensional article which can be coated with a thermoplastic composition. The thickness of these coatings is generally in the range from 0.1 to 3.0 cm, preferably from 0.1 to 2.0 cm and very particularly preferably from 0.5 to 2.0 cm. Such coatings may be produced by processes known in the art, such as lamination, painting, dipping, spraying, application.

Accordingly, a further aspect of the invention is the use of a thermoplastic molding compound according to the invention for a coating composition or for the production of fibers, films or shaped bodies, a further aspect of the invention is the production of a thermoplastic molding compound according to the invention fibers, films or molded articles.

Example

1. Preparation of polyimide

1.1. Preparation of PMDI-MDI-PDA-tBuOH (PI-1)

Reagents and Reactants:

42.00 g (0.192 mol) of 1,2,4,5-benzenetetracarboxylic dianhydride (PDA)

18.43 g (0.0275 mol) of Lupranat® M20 (oligomeric MDI, polyMDI, PMDI)

6.88 g (0.0275 mol) of MDI

29.47 g (0.398 mol) of tert-butanol

144.2 ml NMP

Reaction procedure:

Dissolve 1,2,4,5-benzenetetracarboxylic dianhydride in NMP at 80° C. while stirring in a standard stirring apparatus comprising a 500 ml four-neck flask equipped with a dropping funnel, Teflon stirrer, reflux condenser and thermometer. did it A mixture of Lupranat® M20 and MDI was added dropwise to the solution under a nitrogen atmosphere, and the oil bath temperature was maintained at 80°C. A slightly exothermic reaction with gas evolution could be observed. The mixture was kept at 80° C. for 3 hours with stirring.

After cooling the reaction mixture to 50° C., tert-butanol was added slowly via a dropping funnel. The course of the reaction was monitored by IR measurement. After the NCO band completely disappeared, the solution was distilled at 80° C. under vacuum (20 mbar) to remove excess tert-butanol.

The polyimide solution was added dropwise to the water bath, whereby the polyimide was precipitated as a yellow powder.

1.2. Preparation of additional polyimides

Additional polyimides were prepared analogously to the manufacturing procedure of 1.1. All compositions of polyimides are clear from the table below:

2. Manufacture of molding materials

To prepare molding compounds (FM-1 to FM-5), a mixture of polyimide and polybutylene terephthalate (Ultradur® B4500, PBT) was added in an amount of 15 g to an Xplore MC 15 mini extruder, and for 3 minutes The mixture was mixed at a temperature of 260° C. to 300° C. at 80 rpm. The obtained molding compound showed a single T _g value in the DSC measurement. The mixing ratios and the resulting T _g values are summarized in the table below:

As is evident, it is possible to significantly increase the T _g of polybutylene terephthalate with the addition of PI.

To prepare the molding compounds FM6 to FM9, the components are mixed in a ZSK 18 extruder with a barrel temperature of 260° C., a shaft speed of 300 rpm and a throughput of 6 kg/h, pelletized and then dried at 100° C. for 6 hours. dried in the cabinet. A tensile bar was prepared by injection molding at a melting temperature of 260° C. and a molding temperature of 60° C.

The obtained test specimens were tested at 23° C. according to ISO 527. The results obtained are summarized in the table below.

The glass fibers used were E-glass fibers imparted with an epoxy size; Staple fibers were used.

Molding compounds reinforced with glass fibers exhibit surprisingly higher stiffness and strength as well as increased glass transition temperature.

Claims (16)

A thermoplastic molding compound comprising polyalkylene terephthalate and a polyimide, wherein the thermoplastic molding compound has a single glass transition temperature as measured by DSC. The thermoplastic molding compound according to claim 1 , wherein the single glass transition temperature has a value of at least 45°C, preferably a value of at least 50°C. 3. Thermoplastic according to claim 1 or 2, wherein the polyalkylene terephthalate is polyethylene, polytrimethylene or polybutylene terephthalate or mixtures thereof, wherein the polyalkylene terephthalate is preferably polybutylene terephthalate. molding compound. 3. Thermoplastic molding compound according to claim 1 or 2, wherein the polyimide is obtained by reaction of at least one carboxylic dianhydride with at least one isocyanate, wherein the isocyanate comprises at least two isocyanate groups. 5. The thermoplastic molding compound of claim 4, wherein the at least one carboxylic dianhydride is 1,2,4,5-benzenetetracarboxylic anhydride. 6. The method of claim 4 or 5, wherein the at least one isocyanate is 4,4'-diphenylmethane diisocyanate, oligomeric 4,4'-diphenylmethane diisocyanate, 2,4-toluene diisocyanate or 2,6 - Thermoplastic molding compounds which are toluene diisocyanate or mixtures thereof. 7. A method according to any one of claims 4 to 6, wherein at least three isocyanates, preferably oligomeric 4,4'-diphenylmethane diisocyanate, 2,4-toluene diisocyanate and 2,6-toluene diisocyanate A thermoplastic molding compound in which a mixture of 8. The molar ratio of 2,4-toluene diisocyanate to 2,6-toluene diisocyanate according to claim 7, wherein the molar ratio is from 1:1 to 10:1, preferably from 1.5:1 to 8:1, more preferably from 2:1. to 6:1, more preferably 3:1 to 5:1, in particular 4:1. 9. The molar ratio according to claim 7 or 8, wherein the molar ratio of oligomeric 4,4'-diphenylmethane diisocyanate to the sum of 2,4-toluene diisocyanate and 2,6-toluene diisocyanate is from 1:1 to 0.1:1. , preferably in the range from 0.8:1 to 0.2:1, more preferably from 0.7:1 to 0.3, more preferably from 0.5:1 to 0.4:1. 10. The method according to any one of claims 4 to 9, wherein the reaction of at least one carboxylic dianhydride with at least one isocyanate is followed by reaction with an alcohol or an amine, preferably an alcohol, in particular tert-butanol. A thermoplastic molding compound wherein unconverted isocyanate groups are reacted. 11. Thermoplastic molding compound according to any one of claims 1 to 10, wherein the polyimide has an isocyanate content of less than 1% by weight, based on the total weight of the polyimide, and is preferably isocyanate-free. 13. The method according to any one of claims 1 to 12, wherein the ratio of the weight fraction of polyalkylene terephthalate to polyimide is from 1:1 to 9.9:1, preferably from 2:1 to 9:1, more preferably is in the range of 3:1 to 4:1. 13 . The thermoplastic molding compound according to claim 1 , wherein the proportion of polyalkylene terephthalate, based on the total weight of the molding compound, is at least 50% by weight. The thermoplastic molding compound according to claim 1 , wherein reinforcing fibers, in particular glass fibers, are also present. Use of the thermoplastic molding compound according to any one of claims 1 to 14 as a coating or for producing fibers, films or moldings. 15. A fiber, film or molded body made from the thermoplastic molding compound according to any one of claims 1 to 14.